Wadler's Blog

27.1.14

Off the Beaten Track: False Starts

Saturday I had the pleasure to attend Off the Beaten Track, a workshop of POPL 2014. Every single talk was introduced with the phrase 'And now for something completely different ...'

One talk, by Nada Amin and Tiark Rompf (delivered by Nada), argues that 'papers should expose the sausage-factory of designing calculi, and the minefields in the landscape'.

Ever since Euler (at least), papers in mathematics tend to present a polished solution at the cost of hiding the insights that led to the solution's discovery. Only rarely does one see papers that describe an approach that failed, even though, arguably, knowing what not to do can be as important as knowing what to do.

This leads me to make a suggestion. Every paper is expected to contain sections, where relevant, on
design, implementation, performance, theory, and related work. We should also include, where relevant, a section on 'false starts': research directions that failed to pan out. That is, 'false starts' should be on the checklist of what to cover when first organising a paper. Papers with such material exist, but they are rare; we should make them a common case.

Even committed Zionists are beginning to understand that Israel is consistently violating fundamental human rights in Palestine. This article, by a lawyer, focusses on how Palestinian children fare. Spotted via JFJFP.

By David Middleburgh, Jewish ChronicleJanuary 17, 2014

I have just returned from a three-day tour of the West Bank and east Jerusalem, organised by the pro-Israel, pro-peace organisation, Yachad. The participants were all passionate Zionists and, were it not for some grey hairs and wrinkles, we could have been a youth group. In fact, we were all senior lawyers or individuals with a particular interest in the rule of law.

The purpose: to understand the legal context to the occupation. The centrepiece, a unique visit to the IDF military courts that maintain law and order (for Palestinians only) in the West Bank, unique in that we were the first organised group of British Jews to visit the courts. In the course of the tour we met a very broad spectrum of people from representatives of Israeli NGOs, a senior employee of the Yesha Council, which represents settlers, and a senior adviser to Foreign Minister Avigdor Lieberman.

Arrest of child

My conclusions? First, there is no substitute for finding out what is really happening on the ground by visiting and asking difficult questions. I had made numerous assumptions from both Jewish and non-Jewish media, which were simply wrong.

Secondly, those who consider that stories of systemic breaches of human rights under the occupation are an anti-Israel myth are deluding themselves.

We spent a morning at the military courts observing young Palestinian boys, aged 13-17, being processed, and speaking to their mothers. It is clear that children are invariably arrested in night raids by the army at gunpoint, cuffed and blindfolded and held, often for hours, in that condition, denied access to food, water and toilet facilities, interrogated without being advised of their rights, without a lawyer and without their parents.

Boy arrested by IDF, Nabi Saleh, 2011

Military Court Watch, an Israeli NGO, has carried out a detailed forensic review and they found over 50 per cent of children were arrested in night raids and 83 per cent of children blindfolded. All of the children we saw in court were in leg shackles.

There was a shocking passivity of the Palestinians we observed at court. Parents and detained children smiled and joked with each other and we did not see a single case of anger. That’s not to say parents did not care that their children were being imprisoned.

Israeli occupation forces detain a Palestinian youth in the West Bank city of Hebron on 22 September 2013, during protests against road closures for the benefit of Jewish settlers. Photo by Mamoun Wazwaz / APA images

But conviction rates are 99.7 per cent. The passivity bespeaks a people who have become resigned to their reality. They recognise there is no longer any point in fighting for basic rights. I felt that the court system was clearly a figleaf for a system of arbitrary justice where the guilt of the child is beside the point. The courts are part of a system that effectively keeps Palestinian society in a state of constant fear and uncertainty.

So why do the authorities bother with the expense of maintaining the pretence of justice? The answer is that without scrutiny it is possible to pretend that the system is fair. So, defendants are legally represented and proper rules of evidence apply.

Boy arrested on suspicion of throwing stones, Silwan, December 26, 2010. No further information

Arrest of boy, Silwan, 2011. No further information.

A much reproduced photo, for obvious reasons of a police swoop on young boys in Jerusalem, 2010. No further information.

Scrape away the veneer, and the charade is exposed with convictions routinely obtained based upon forced confessions and defendants facing remand without bail pending trial for periods in excess of sentences when pleading guilty. No sane defendant would plead not guilty in this Catch 22 situation.

I would argue that diaspora Jews who are true friends of Israel have a duty to visit the territories to understand the problem, and then to lobby friends in Israel to strive for a just end to this situation.

If we do nothing, can we complain if we awake one day and Israel has sleepwalked into the status of a pariah country?

David Middleburgh is a partner in the London firm of Gallant Maxwell solicitors

24.1.14

Gagging Law---still a problem

I had the following e-mail from my MP, Ian Murray; reprinted with permission. Photo shows 38 Degrees lobbying Murray's office last December. He is 3'rd from right, I am 3'rd from left.

I'm backing amendments to the Lobbing Bill today

But the truth is that this terrible bill should be binned

Thank you for contacting me about the Lobbying Bill. While some of you have contacted me for the first time this week, I have been keeping the majority of you up to date throughout this process. We are nearing the end of the bill's progress now, as today we begin the 'ping-pong' of amendments between the Lords and the Commons.

I must praise the work of 38 Degrees and other organisations in campaigning so hard on this issue. More people have contacted me on this bill than any other since the election in 2010. I had the pleasure of meeting a small number of campaigners from 38 Degrees towards the end of last year (picture above). They handed me a petition of thousands of people from across the UK firmly against the bill.

Standing up for the wrong people

The government have got themselves in to a real mess with this gagging bill. After being forced in to a panic pause on part two they then had to grant a series of concessions. While those concessions make a bad bill slightly better, they don’t go far enough and the gag on charities and campaigners remains firmly in place.

That is why it is so important that the Commons votes to keep the two amendments that the Lords defeated the government on – the exclusion of some staff costs from the slashed spending limit, and the inclusion of special advisors in the definition of those who can be lobbied. I will be voting to keep those amendments in the bill and I will urge my colleagues to do the same.

Only David Cameron could present a Lobbying Bill that doesn’t stop commercial lobbyists influencing government policy, but could stop charities and campaigners from campaigning about it. No wonder people think he stands up for the wrong people.

This has been a bad bill from word go, and the government should’ve just gone back to the drawing board.

I have been leading for the Labour Party on part three of this bill, and have been pushing to make it a better piece of legislation. Unfortunately the government haven't listened to the thousands of people pushing to scrap this bill.

Thank you once again for getting in touch.

Yours sincerely,

Ian Murray MPWorking Hard for South Edinburgh The next day, I had the following update from 38 Degrees.

Dear Philip,

Here's a quick update on how it went today, with MPs voting again on the gagging law.

I’m afraid it's bad news. Most Conservative and Liberal Democrat MPs chose to follow party orders. They reversed the main improvements made in the House of Lords.

This means they voted:
- to remove new rules limiting secret lobbying by big business
- to put back in key limits on what campaigners, charities, and voluntary groups can do to speak up on issues of the day [1]

It’s pretty depressing. But it’s not over. The House of Lords will now get another vote – probably next week. They have the option to refuse to back down, and force MPs to vote yet again.

The votes were quite close. A number of government MPs did rebel - thanks in no small part to all the petitions, leaflets, emails and events which 38Degrees members like you made happen.

If 17 more Conservative or Lib Dem MPs had voted differently, we would have won. Maybe we can get some more to change their minds next time around?

Details of how each MP voted will be posted on the 38Degrees website, as soon as they are published (probably tomorrow morning).

All of us will need to think quickly about what we do next to stand up for democracy and freedom of speech. Options could include:
- a fresh push to encourage the Lords to hold firm next week
- naming and shaming MPs who voted to make the gagging law worse again today and pushing them to change their minds
- looking at options for legal challenges to the gagging law’s provisions
- thinking through ways we can keep campaigning and speaking up on the issues that matter despite the gagging law

Today, there's lots to feel fed up about. Yet again we’ve seen MPs push through a law which the public have never voted for, and which has been heavily criticised by everyone from the United Nations to the Citizens Advice Bureau, the Women’s Institute to the Royal British Legion. [2]

But there are reasons to feel hopeful too. This campaign has brought together so many different organisations and so many people from all walks of life. [3] Together we're proving that whilst faith in politicians is at an all time low, passion for real democracy is alive and kicking.

If you have thoughts or suggestions on what we should do together next, or just want to share how you're feeling, you can join the conversation on the 38Degrees Facebook page, here:https://www.facebook.com/peoplepowerchange

Alternatively, please reply to this email leaving the subject line the same.

I'll look forward to reading your thoughts.

Hopefully we can all agree on one thing, though. This definitely isn’t the time to give up. The kind of issues that 38Degrees members choose to campaign on – like protecting the NHS, preserving our countryside, improving democracy and challenging tax dodging – are way too important to leave to politicians.

An alarming number of politicians seem to want us to shut up. But, I’m very glad to say, we’re just not going to!

PPS: MPs let us down today, but it isn't quite over yet - so please do share your ideas for what we could do next. Either by replying here or by posting on the 38DegreesFacebook page:https://www.facebook.com/peoplepowerchange

NOTES
[1] There were 3 big votes in the Commons today:
- On the vote to require Ministers’ special advisors to record their meetings with lobbyists 311 MPs voted to reject the change, and 258 voted to accept them.
- On the vote to reject Lords’ changes to how much staff costs count towards total spending limits, amendment 108: 310 MPs voted to reject the changes, and 278 MPs to accept them into the Bill
- On the vote to reject Lords’ changes to the scope of what activity counts towards constituency spending limits, amendments 26 and 27: 314 MPs voted to reject the changes, and 274 MPs to accept them

22.1.14

My somewhat elliptic title refers, of course, to the programmer; so much you may have guessed. What, in all probability, you could not have guessed, is that I have chosen to use the words "craftsman" and "scientist" in a very specific meaning: they have been chosen to characterize the results of two extreme techniques of education, and this luncheon speech will be devoted to a (be it short) discussion of their role in the education of programmers, in the teaching of programming. For the transmission of knowledge and skills both techniques have been used side by side since many centuries.

A letter from Edsgar Dijkstra, written in 2001, argues that Haskell, not Java, should be used to teach introductory programming at the University of Texas. Blogged by Chris Done, spotted by Shayan Najd.

Colleagues from outside the state (still!) often wonder how I can survive in a place like Austin, Texas, automatically assuming that Texas’s solid conservatism guarantees equally solid mediocrity. My usual answer is something like “Don’t worry. The CS Department is quite an enlightened place, for instance for introductory programming we introduce our freshmen to Haskell”; they react first almost with disbelief, and then with envy —usually it turns out that their undergraduate curriculum has not recovered from the transition from Pascal to something like C++ or Java.

I enjoy well-presented talks---not least so I can steal ideas about how to present well for my own talks---and TED is a great source of these. My ambition is to present at TED one day. Nonetheless, this analysis points out an interesting problem with TED. My ambition is unchanged and I'll keep watching the talks, but perhaps with a more skeptical eye. Spotted via Boing Boing.

19.1.14

Zak Ziebell, then a 17-year-old San Antonio senior, challenged 30 people to sketch a map of the world, then combined them into a vague smudge. Then he produced this unnervingly realistic map of the alternative Earth lurking in his subjects' collective memories.

18.1.14

David Donnison on Bella Caledonia presents a concise argument for independence that puts, far better than I could, my own views.

They asked me about many of the dilemmas we have been pondering in Scotland in the aftermath of our white paper – and most of them could not understand why any intelligent Scot would be voting for independence. It was an afternoon that compelled me to clarify my own thinking.
What matters most, I said, is not how an independent Scotland will fare. Independence will of course bring teething troubles of many kinds; but the Scots, if they choose to break away, will make their way in the world pretty successfully. What matters most, I said, is what you are doing in England; what kind of country you want to make of the UK; and whether we in Scotland want to be part of it.
...
The Scottish ‘political class’ assume that proposals for new policies should help to create a fairer and more equal society where there will be greater social justice. They assume that proposals for solving social problems should be prepared in active consultation with the kinds of people who experience these problems. Of course they do not always live up to these aspirations; but our political class assume that they will be generally accepted by Scottish governments, whoever wins our next elections. They are not contentious. None of that can be said of England.
I could give various examples of the impact of these divergent cultures, but one will have to do. When our first minister was taking questions at the press conference launching the independence white paper, a correspondent from the Daily Telegraph said (roughly speaking – I took no note): ‘Your plans for Scotland’s future are splendid. But in a country with high rates of unemployment and high proportions of pensioners, how can you pay for all this?’ To which Salmond replied: ‘That would indeed be difficult if nothing changes. But an independent Scotland will attract more young workers’. To which the Telegraph man – thinking he had a killer question – said: ‘You mean more immigrants?’. ‘Yes,’ said Salmond. ‘They make an important and creative contribution to our society and we need more of them.’ Could any serious English politician have said this? And if it had been said, would it have passed unnoticed, as it did in Scotland?
...
We shall all have to make our best guesses at England’s political trends when the referendum comes – eight months before the next Westminster election which may give us a few pointers. But if staying in the UK seems likely to mean living in a country that leaves the European Union (Miliband, if he wins the election, has not yet promised a referendum on that, but neither has he refused one); if it is to be a country that continues to impose increasingly punitive and humiliating sanctions on its poorest citizens who live on social security benefits (Labour spokespersons on this subject seem determined to show they will match the Tories’ brutalities); if the Human Rights Act is to be repealed (as our present home secretary promises); if the UK continues to have the most centralised government in the Western world (strangling local governments and killing off civic leadership); if ‘green’ policies are to have low priority; and if our armed forces are to remain mercenary outriders to American foreign policy; then I would rather get out, whatever the hazards of independence.
It’s a white paper, agreed by the main political parties, on the future plans and priorities, not of Scotland but of the rest of the UK, that I need. I guess I’ll have to place my bet without waiting for that.

15.1.14

ADT and GADT implementations of simply-typed lambda calculus

Lennart Augustsson posted a nifty description of a compiler from a simple expression language to LLVM that included a conversion from expressions represented as an ADT to expressions represented as a GADT. The ADT requires a separately implemented type checker, while the GADT piggybacks on Haskell's type system to ensure expressions are well typed. However, Lennart's expression language does not include lambda abstraction.

Based on Lennart's code, I implemented ADT and GADT versions of simply-typed lambda calculus with de Bruijn indices, integer constants, and addition, plus the conversion between them, without the distraction of compiling to LLVM. The code was cleaned and improved by Shayan Najd, and made publicly available via github. Thanks to Josef Svenningson for the pointer to Lennart's post.

12.1.14

Scotland, the UK, and the UFP

@PhilipWadler I'm proudly for Scottish identity but shouldn't our species look to the stars and remove borders, not remake old ones?

Good question. I approve of the United Nations and (alluding to @delitescere's wording) the United Federation of Planets. So why should I agitate to undo the 1707 Act of Union?

While my knee-jerk reaction is to support larger groupings, upon reflection I realise that the issues are not so clear cut. In favour is the argument for peace: the UK, the EU, and the UN (not to mention the UFP) promote resolution of conflict by negotiation, avoiding warfare—clearly a good thing. Neither in favour nor opposed is the argument for trade: while removing trade barriers is a good thing, organisations like NAFTA and the WTO can impose the agenda of prosperous nations against the interests of the less prosperous. Opposed is the argument that democracy is more effective at a smaller scale: it is easier to make an electoral impact in Edinburgh that in Scotland, in Scotland than the UK, in the UK than in the EU, and in the EU than the world. Though my heart yearns for World Government (or a Federation of Planets), my head finds the issues more equivocal.

How do these arguments play out when considering independence for Scotland? On the issues of peace and trade, independence will have little impact. While there are many uncertainties concerning independence, none believe it will lead to war and it seems unlikely to seriously impair trade. It is the issue of democracy that I find most compelling in this case.

I want to live in a country that promotes education, provides for the health of its citizens, takes good care of its elderly, and eschews nuclear weapons. Scottish voters support free tuition for higher education, free prescriptions under the NHS, free personal care for everyone aged over 65, and oppose Trident nuclear submarines. The UK as a whole takes none of these positions. Britain faces grave economic decisions, and I trust Scots to make a better fist of these than I do the entirety of the UK. For me, it is the argument for local democracy that carries the day.

Haskell in XKCD

Scots have nothing to lose going the ‘indy’ route

Iain Robertson presents a concise summary of the argument for Scottish independence. From The Japan Times of all places, and March 2013 of all times.

Under the current devolved settlement, Scotland has a parliament sitting in Holyrood, Edinburgh, which controls a paltry 16 percent of the country’s tax base. The game-changing economic and social policy levers remain in the hands of the U.K. government, leaving Scotland unable to properly tackle some of its social ills or take full advantage of its many natural resources.Scotland’s union with England and the other parts of the U.K. is not offering Scots the best option. The current political landscape across the nations of the U.K. is one where Westminster is controlled by a Conservative-Liberal coalition government that was roundly rejected by Scottish voters at the last election; just one Conservative member of Parliament hails from a seat north of the border....Recent figures revealed in “The Government Expenditure and Revenue Scotland 2011-12 Report” show that, rather than enjoying handouts, Scotland is paying more money in tax than it receives in U.K. public spending, to the tune of around £863 per head of its population.Newspapers the length and breadth of the U.K. continue to run baseless front-page scare stories about independence. What many of these failing newspapers make clear is that the so-called “union” of countries is viewed by London as being one they control.There is even more to Scotland’s economic potential as an independent country than its booming oil and renewable energy industries. It has a number of world- class business sectors; including food and drink, life sciences and a first-class education system. Scotland has much to offer — both to itself and the world....There is even more to Scotland’s economic potential as an independent country than its booming oil and renewable energy industries. It has a number of world- class business sectors; including food and drink, life sciences and a first-class education system. Scotland has much to offer — both to itself and the world....As Scots singer Eddie Reader retweeted: “indy (independence) gives us uncertainty with power, U.K. gives uncertainty without power.”